Aromatase Inhibitors
Compounds that inhibit AROMATASE in order to reduce production of estrogenic steroid hormones.
Triazoles
Nitriles
Fadrozole
A selective aromatase inhibitor effective in the treatment of estrogen-dependent disease including breast cancer.
Aromatase
An enzyme that catalyzes the desaturation (aromatization) of the ring A of C19 androgens and converts them to C18 estrogens. In this process, the 19-methyl is removed. This enzyme is membrane-bound, located in the endoplasmic reticulum of estrogen-producing cells of ovaries, placenta, testes, adipose, and brain tissues. Aromatase is encoded by the CYP19 gene, and functions in complex with NADPH-FERRIHEMOPROTEIN REDUCTASE in the cytochrome P-450 system.
Androstatrienes
Antineoplastic Agents, Hormonal
Antineoplastic agents that are used to treat hormone-sensitive tumors. Hormone-sensitive tumors may be hormone-dependent, hormone-responsive, or both. A hormone-dependent tumor regresses on removal of the hormonal stimulus, by surgery or pharmacological block. Hormone-responsive tumors may regress when pharmacologic amounts of hormones are administered regardless of whether previous signs of hormone sensitivity were observed. The major hormone-responsive cancers include carcinomas of the breast, prostate, and endometrium; lymphomas; and certain leukemias. (From AMA Drug Evaluations Annual 1994, p2079)
Tamoxifen
One of the SELECTIVE ESTROGEN RECEPTOR MODULATORS with tissue-specific activities. Tamoxifen acts as an anti-estrogen (inhibiting agent) in the mammary tissue, but as an estrogen (stimulating agent) in cholesterol metabolism, bone density, and cell proliferation in the ENDOMETRIUM.
Androstenedione
A delta-4 C19 steroid that is produced not only in the TESTIS, but also in the OVARY and the ADRENAL CORTEX. Depending on the tissue type, androstenedione can serve as a precursor to TESTOSTERONE as well as ESTRONE and ESTRADIOL.
Aminoglutethimide
An aromatase inhibitor that is used in the treatment of advanced BREAST CANCER.
Postmenopause
Neoplasms, Hormone-Dependent
Estrogens
Compounds that interact with ESTROGEN RECEPTORS in target tissues to bring about the effects similar to those of ESTRADIOL. Estrogens stimulate the female reproductive organs, and the development of secondary female SEX CHARACTERISTICS. Estrogenic chemicals include natural, synthetic, steroidal, or non-steroidal compounds.
Estrogen Antagonists
Androstadienes
Estradiol
Receptors, Estrogen
Cytoplasmic proteins that bind estrogens and migrate to the nucleus where they regulate DNA transcription. Evaluation of the state of estrogen receptors in breast cancer patients has become clinically important.
Estrogen Receptor Modulators
Testolactone
Chemotherapy, Adjuvant
Selective Estrogen Receptor Modulators
A structurally diverse group of compounds distinguished from ESTROGENS by their ability to bind and activate ESTROGEN RECEPTORS but act as either an agonist or antagonist depending on the tissue type and hormonal milieu. They are classified as either first generation because they demonstrate estrogen agonist properties in the ENDOMETRIUM or second generation based on their patterns of tissue specificity. (Horm Res 1997;48:155-63)
Testosterone
A potent androgenic steroid and major product secreted by the LEYDIG CELLS of the TESTIS. Its production is stimulated by LUTEINIZING HORMONE from the PITUITARY GLAND. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to DIHYDROTESTOSTERONE or ESTRADIOL.
Estrone
An aromatized C18 steroid with a 3-hydroxyl group and a 17-ketone, a major mammalian estrogen. It is converted from ANDROSTENEDIONE directly, or from TESTOSTERONE via ESTRADIOL. In humans, it is produced primarily by the cyclic ovaries, PLACENTA, and the ADIPOSE TISSUE of men and postmenopausal women.
Gynecomastia
Enlargement of the BREAST in the males, caused by an excess of ESTROGENS. Physiological gynecomastia is normally observed in NEWBORNS; ADOLESCENT; and AGING males.
Enzyme Inhibitors
Receptors, Progesterone
Specific proteins found in or on cells of progesterone target tissues that specifically combine with progesterone. The cytosol progesterone-receptor complex then associates with the nucleic acids to initiate protein synthesis. There are two kinds of progesterone receptors, A and B. Both are induced by estrogen and have short half-lives.
Megestrol Acetate
Megestrol acetate is a progestogen with actions and uses similar to those of the progestogens in general. It also has anti-androgenic properties. It is given by mouth in the palliative treatment or as an adjunct to other therapy in endometrial carcinoma and in breast cancer. Megestrol acetate has been approved to treat anorexia and cachexia. (From Reynolds JEF(Ed): Martindale: The Extra Pharmacopoeia (electronic version). Micromedex, Inc, Englewood, CO, 1995)
Estrogen Receptor alpha
One of the ESTROGEN RECEPTORS that has marked affinity for ESTRADIOL. Its expression and function differs from, and in some ways opposes, ESTROGEN RECEPTOR BETA.
Ovary
The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.
Clinical Trials as Topic
Works about pre-planned studies of the safety, efficacy, or optimum dosage schedule (if appropriate) of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects. This concept includes clinical trials conducted both in the U.S. and in other countries.
Androgens
Compounds that interact with ANDROGEN RECEPTORS in target tissues to bring about the effects similar to those of TESTOSTERONE. Depending on the target tissues, androgenic effects can be on SEX DIFFERENTIATION; male reproductive organs, SPERMATOGENESIS; secondary male SEX CHARACTERISTICS; LIBIDO; development of muscle mass, strength, and power.
Drug Resistance, Neoplasm
Puberty, Precocious
Development of SEXUAL MATURATION in boys and girls at a chronological age that is 2.5 standard deviations below the mean age at onset of PUBERTY in the population. This early maturation of the hypothalamic-pituitary-gonadal axis results in sexual precocity, elevated serum levels of GONADOTROPINS and GONADAL STEROID HORMONES such as ESTRADIOL and TESTOSTERONE.
Papio anubis
Hot Flashes
Dihydrotestosterone
A potent androgenic metabolite of TESTOSTERONE. It is produced by the action of the enzyme 3-OXO-5-ALPHA-STEROID 4-DEHYDROGENASE.
Endometriosis
A condition in which functional endometrial tissue is present outside the UTERUS. It is often confined to the PELVIS involving the OVARY, the ligaments, cul-de-sac, and the uterovesical peritoneum.
Sex Differentiation
The process in developing sex- or gender-specific tissue, organ, or function after SEX DETERMINATION PROCESSES have set the sex of the GONADS. Major areas of sex differentiation occur in the reproductive tract (GENITALIA) and the brain.
Follicle Stimulating Hormone
A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Follicle-stimulating hormone stimulates GAMETOGENESIS and the supporting cells such as the ovarian GRANULOSA CELLS, the testicular SERTOLI CELLS, and LEYDIG CELLS. FSH consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity.
Clomiphene
A triphenyl ethylene stilbene derivative which is an estrogen agonist or antagonist depending on the target tissue. Note that ENCLOMIPHENE and ZUCLOMIPHENE are the (E) and (Z) isomers of Clomiphene respectively.
Bone Density Conservation Agents
Treatment Outcome
Neoadjuvant Therapy
Gonads
The gamete-producing glands, OVARY or TESTIS.
Estrogen Receptor beta
One of the ESTROGEN RECEPTORS that has greater affinity for ISOFLAVONES than ESTROGEN RECEPTOR ALPHA does. There is great sequence homology with ER alpha in the DNA-binding domain but not in the ligand binding and hinge domains.
Gonadotropins
Hormones that stimulate gonadal functions such as GAMETOGENESIS and sex steroid hormone production in the OVARY and the TESTIS. Major gonadotropins are glycoproteins produced primarily by the adenohypophysis (GONADOTROPINS, PITUITARY) and the placenta (CHORIONIC GONADOTROPIN). In some species, pituitary PROLACTIN and PLACENTAL LACTOGEN exert some luteotropic activities.
Luteinizing Hormone
A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity.
Receptor, erbB-2
A cell surface protein-tyrosine kinase receptor that is overexpressed in a variety of ADENOCARCINOMAS. It has extensive homology to and heterodimerizes with the EGF RECEPTOR, the ERBB-3 RECEPTOR, and the ERBB-4 RECEPTOR. Activation of the erbB-2 receptor occurs through heterodimer formation with a ligand-bound erbB receptor family member.
Randomized Controlled Trials as Topic
Mammary Neoplasms, Experimental
Experimentally induced mammary neoplasms in animals to provide a model for studying human BREAST NEOPLASMS.
Ovulation Induction
Placenta
A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (CHORIONIC VILLI) derived from TROPHOBLASTS and a maternal portion (DECIDUA) derived from the uterine ENDOMETRIUM. The placenta produces an array of steroid, protein and peptide hormones (PLACENTAL HORMONES).
Puberty, Delayed
The lack of development of SEXUAL MATURATION in boys and girls at a chronological age that is 2.5 standard deviations above the mean age at onset of PUBERTY in a population. Delayed puberty can be classified by defects in the hypothalamic LHRH pulse generator, the PITUITARY GLAND, or the GONADS. These patients will undergo spontaneous but delayed puberty whereas patients with SEXUAL INFANTILISM will not.
Fibrous Dysplasia, Polyostotic
Steroids
A group of polycyclic compounds closely related biochemically to TERPENES. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (STEROLS), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. (From Hawley's Condensed Chemical Dictionary, 11th ed)
Diphosphonates
Organic compounds which contain P-C-P bonds, where P stands for phosphonates or phosphonic acids. These compounds affect calcium metabolism. They inhibit ectopic calcification and slow down bone resorption and bone turnover. Technetium complexes of diphosphonates have been used successfully as bone scanning agents.
Double-Blind Method
Drug Administration Schedule
Bone Density
The amount of mineral per square centimeter of BONE. This is the definition used in clinical practice. Actual bone density would be expressed in grams per milliliter. It is most frequently measured by X-RAY ABSORPTIOMETRY or TOMOGRAPHY, X RAY COMPUTED. Bone density is an important predictor for OSTEOPOROSIS.